1. Field of the Invention
This invention concerns a method for promoting dental hygiene in particular by reducing plaque, whitening teeth, preventing tooth demineralization and providing tooth remineralization. The method employs a chewing gum or confectionery product containing as active ingredients, a combination of sodium bicarbonate and casein phosphopeptide-amorphous calcium phosphate. The invention also concerns the chewing gums and confectionery products that can provide dental health benefits and methods for their preparation.
2. Description of the Prior Art
The formation of dental caries in teeth has been well studied. Caries are understood to result from the accumulation of plaque on the teeth and the production of organic acids (plaque acids) when plaque microorganisms ferment sugars and starches in food. Before being washed away by saliva, the acids accumulate in the plaque long enough to lower the pH and to cause some of the enamel, a calcium-phosphorous mineral known as hydroxyapatite, to dissolve, that is, demineralize, which can lead to dental caries (tooth decay), and sensitivity.
Plaque itself which is a sticky film of the oral bacteria and their products, can become calcified with the ultimate formation of a hard mineral on the teeth. Calculus, or tartar as it is sometimes called, is the solid, hard mass of calcified material deposited on and adhering to the surfaces of the teeth. As mature calculus develops it becomes visibly white or yellowish in color. Plaque formation can lead to gingivitis and subsequent periodontal disease.
Efforts have been made over the years to address the problem of plaque accumulation and the dissolution or demineralization of tooth enamel and the resultant formation of dental caries.
It is known to use sodium bicarbonate (NaHCO3), in dental care for the purpose of reducing plaque and whitening teeth, and further for reducing oral malodor. Also known as baking soda or bicarbonate of soda or carbonic acid monosodium salt, sodium bicarbonate has long been used in dentrifrices such as pastes and oral rinses, often in combination with sodium chloride. It can buffer plaque acids, which cause demineralization of teeth, by returning the oral pH to a more favorable pH. In high concentrations, it is bactericidal against most periodontal pathogens. Sodium bicarbonate has found recent favor over alternatives for its low cost, safety if ingested, low abrasivity due to its high solubility, and compatibility with fluoride. Sodium bicarbonate has been used in chewing gums as a filler, a buffer, a dental plaque remover, as an abrasive when used in higher amounts.
U.S. Pat. No. 3,590,120 teaches a chewing gum containing a dental plaque removal agent and a dental polishing agent. Sodium bicarbonate is taught as a dental plaque removal agent. U.S. Pat. No. 4,170,633 discloses chewing gums for delivering alkyl sulfates as plaque inhibiting agents. Sodium bicarbonate is used as a buffer. U.S. Pat. No. 4,952,407 teaches chewing gums for reducing dental plaque containing glycerol mono laurate. Sodium bicarbonate is used as a filler. U.S. Pat. Nos. 5,702,687, 5,693,334, 5,618,517, and 5,629,035 teach chewing gums for dental care which contain organically encapsulated sodium bicarbonate.
Casein phosphopeptides-amorphous calcium phosphate complexes are known to have anticariogenic teeth strengthening effects when used as dentrifrices. The complexes, also known as CPP-ACP complexes or calcium casein peptone-calcium phosphate are amorphous calcium phosphate stabilized by casein phosphopeptides. CPP-ACP depresses demineralization and enhances remineralization while buffering plaque acid. It acts by localizing calcium and phosphate ions in dental plaque at the tooth surface. This increased level of calcium and phosphate in dental plaque helps buffer plaque acid and maintain a state of supersaturation of calcium and phosphate in solution. i.e. in the saliva. The use of casein phosphopeptides alone for prevention of caries and plaque formation is also known. The use of chewing gum as a carrier for CPP-ACP has been suggested.
U.S. Pat. Nos. 5,130,123 and 5,227,154 teach casein phosphopeptides in prevention of dental caries. WO 98/40406 teaches phosphopeptide-calcium phosphate complexes to provide anti-caries efficacy.
While it would be very desirable to combine in one delivery system the plaque reduction and tooth whitening benefits of sodium bicarbonate with the remineralization and strengthening of teeth provided by CPP-ACP, it is known that sodium bicarbonate will react with calcium phosphate to form calcium carbonate. Combining sodium bicarbonate with CPP-ACP, would be expected to precipitate calcium carbonate thereby diminishing the supply of calcium ions and concomitantly diminish the efficacy of CPP-ACP. A combination of the two dental care components in a system such as traditional oral rinses and pastes, would result in a diminishing or deactivation of the remineralization efficacy of the CPP-ACP.